================================================================== BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:982 [inline] BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:560 [inline] BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x696/0xca0 net/xfrm/xfrm_state.c:830 Write of size 8 at addr ffff888055c05570 by task syz.6.629/8668 CPU: 1 UID: 0 PID: 8668 Comm: syz.6.629 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __hlist_del include/linux/list.h:982 [inline] hlist_del_rcu include/linux/rculist.h:560 [inline] __xfrm_state_delete+0x696/0xca0 net/xfrm/xfrm_state.c:830 xfrm_timer_handler+0x18f/0xa00 net/xfrm/xfrm_state.c:716 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5225 Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 9f 80 ec 09 e8 ea 41 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc900037b7758 EFLAGS: 00000282 RAX: 9e689a3625e43100 RBX: 0000000000000000 RCX: 9e689a3625e43100 RDX: 0000000000000006 RSI: ffffffff8d9baf27 RDI: ffffffff8be34480 RBP: ffffc900037b77b0 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6 R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: ffff88802ea98000 R13: dffffc0000000000 R14: ffff888028b49e00 R15: ffff8880b873ab58 context_switch kernel/sched/core.c:5360 [inline] __schedule+0x17a0/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 54 6f fe 0b 48 89 de 5b e9 93 53 59 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 f0 a0 92 65 8b 15 78 2a RSP: 0018:ffffc900037b7b40 EFLAGS: 00000286 RAX: ffff888031675e00 RBX: ffff88802f62b340 RCX: 9e689a3625e43100 RDX: ffff88801bad6140 RSI: ffffffff8be34460 RDI: ffffffff8be34420 RBP: 1ffff11005ec5676 R08: 00000000ffffffff R09: 0000000000000000 R10: ffff888031675e00 R11: ffffffff81ac5140 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff888031675e00 R15: ffff88802de6f000 lsm_file_alloc security/security.c:734 [inline] security_file_alloc+0x45/0x330 security/security.c:2888 init_file+0x93/0x2f0 fs/file_table.c:159 alloc_empty_file+0x6e/0x1d0 fs/file_table.c:241 alloc_file fs/file_table.c:354 [inline] alloc_file_pseudo+0x13d/0x210 fs/file_table.c:383 __anon_inode_getfile fs/anon_inodes.c:166 [inline] anon_inode_getfile+0xc5/0x1a0 fs/anon_inodes.c:204 __do_sys_perf_event_open kernel/events/core.c:13662 [inline] __se_sys_perf_event_open+0xf20/0x1d70 kernel/events/core.c:13364 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f926338eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9264274038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f92635e5fa0 RCX: 00007f926338eec9 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000180 RBP: 00007f9263411f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f92635e6038 R14: 00007f92635e5fa0 R15: 00007fff8dda9b98 Allocated by task 7923: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 xfrm_state_alloc+0x24/0x2f0 net/xfrm/xfrm_state.c:733 __find_acq_core+0x8a7/0x1c00 net/xfrm/xfrm_state.c:1833 xfrm_find_acq+0x78/0xa0 net/xfrm/xfrm_state.c:2353 xfrm_alloc_userspi+0x6b3/0xc90 net/xfrm/xfrm_user.c:1863 xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5967: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4797 xfrm_state_free net/xfrm/xfrm_state.c:591 [inline] xfrm_state_gc_destroy net/xfrm/xfrm_state.c:618 [inline] xfrm_state_gc_task+0x52d/0x6b0 net/xfrm/xfrm_state.c:634 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888055c05540 which belongs to the cache xfrm_state of size 928 The buggy address is located 48 bytes inside of freed 928-byte region [ffff888055c05540, ffff888055c058e0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x55c04 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff888142a94500 dead000000000122 0000000000000000 raw: 0000000000000000 00000000000f000f 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff888142a94500 dead000000000122 0000000000000000 head: 0000000000000000 00000000000f000f 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001570101 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6535, tgid 6529 (syz.8.74), ts 151422942873, free_ts 151421589749 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0xbeb/0x1420 mm/slub.c:3901 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4247 xfrm_state_alloc+0x24/0x2f0 net/xfrm/xfrm_state.c:733 xfrm_state_construct net/xfrm/xfrm_user.c:889 [inline] xfrm_add_sa+0x17d1/0x4070 net/xfrm/xfrm_user.c:1019 xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 page last free pid 6528 tgid 6528 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 discard_slab mm/slub.c:2758 [inline] __put_partials+0x156/0x1a0 mm/slub.c:3223 put_cpu_partial+0x17c/0x250 mm/slub.c:3298 __slab_free+0x2d5/0x3c0 mm/slub.c:4565 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 vm_area_dup+0x2b/0x680 mm/vma_init.c:122 __split_vma+0x1a9/0xa00 mm/vma.c:515 vms_gather_munmap_vmas+0x4ce/0x12f0 mm/vma.c:1380 __mmap_prepare mm/vma.c:2359 [inline] __mmap_region mm/vma.c:2651 [inline] mmap_region+0x724/0x20c0 mm/vma.c:2739 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff888055c05400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055c05480: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc >ffff888055c05500: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ^ ffff888055c05580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055c05600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 0f 84 3c 01 00 00 je 0x142 6: 48 85 db test %rbx,%rbx 9: 0f 85 63 01 00 00 jne 0x172 f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 14: 4c 8b 75 d0 mov -0x30(%rbp),%r14 18: 4c 89 e7 mov %r12,%rdi 1b: e8 9f 80 ec 09 call 0x9ec80bf 20: e8 ea 41 36 00 call 0x36420f 25: fb sti 26: 4c 8b 65 c0 mov -0x40(%rbp),%r12 * 2a: 49 8d bc 24 18 16 00 lea 0x1618(%r12),%rdi <-- trapping instruction 31: 00 32: 48 89 f8 mov %rdi,%rax 35: 48 c1 e8 03 shr $0x3,%rax 39: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax 3e: 84 c0 test %al,%al